This invention relates generally to microwave oscillators and more particularly to a microwave oscillator utilized in a microwave integrated circuit configuration.
Prior art forms of microwave oscillators utilizing semiconductor negative resistance elements particularly adapted for use in microwave integrated circuits such as disclosed in U.S. Pat. No. 3,842,360 entitled "Parametric Amplifier", L. E. Dickens have had an inherent limitation due to the fact that excessive circuit losses prohibit the attainment of a reasonable quality Q factor and thus the ability to obtain a relatively narrow bandwidth resonance is lacking. For example, the unloaded Q of conventional resonant elements in microwave integrated circuits formed on alumina substrates, having thicknesses in the order of 0.025 in., typically are in the range of 100-300 for operational frequencies in the 1-10 GHz range. For very narrow oscillation line widths, however, the required loaded Q may exceed 1000. Thus the loaded Q requirements of a microwave oscillator of the type referred to above exceeds the unloaded Q capability and thus a fundamental incompatability results.